Skin, Soft Tissue, and Bone Infections IMPETIGO, ABSCESSES, CELLULITIS, AND ERYSIPELA

Boils and carbuncles Boils and carbuncles are painful, pus-filled bumps Form under skin when bacteria infect and inflame one or more of hair follicles

Boils (furuncles) usually start as red, tender lumps lumps quickly fill with pus growing larger and more painful until they rupture and drain Boils can occur anywhere on the skin appear mainly on face, neck, armpits, buttocks or thighs hair-bearing areas where most likely to sweat

A carbuncle is a cluster of boils Could be care for a single boil at home don't attempt to prick or squeeze it that may spread the infection Patient must see a doctor if its extremely painful lasts longer than two weeks occurs with a fever Furuncle

Causes Boils usually form when one or more hair follicles become infected with Staphylococcus aureus Staph bacteria that cause boils generally enter through a cut, scratch or other break in your skin As soon as this occurs, neutrophils rush to the site to fight the infection leads to inflammation and eventually to the formation of pus

Signs and symptoms A painful, red bump that starts out about the size of a pea Red, swollen skin around the bump An increase in the size of the bump over a few days as it fills with pus can sometimes reach the size of a golf ball

Once the boil drains, the pain usually subsides Development of a yellow-white tip that eventually ruptures and allows the pus to drain out Once the boil drains, the pain usually subsides Small boils usually heal without scarring but a large boil may leave a scar

Carbuncles A carbuncle is a cluster of boils that often occurs on the back of the neck, shoulders or thighs Carbuncles Cause a deeper and more severe infection than single boils do Develop and heal more slowly than single boils do Are likely to leave a scar Signs and symptoms that may accompany carbuncles include Feeling unwell in general Fever Chills

Carbuncle

Risk factors Although anyone can develop boils or carbuncles, the following factors can increase the risk Close contact with a person who has a staph infection Diabetes Other skin conditions Compromised immunity

Complications Complications of boils and carbuncles are generally few, but can be serious They include Blood poisoning MRSA

Tests and diagnosis Considering signs, symptoms and medical history and looking at distinctive sores You may culture the drainage if recurring infections infections that don't respond to standard treatment patient with a weakened immune system

Treatments and drugs Small boils could be treated at home By applying warm compresses relieve pain promote natural drainage For larger boils and carbuncles treatment usually includes draining the boil with an incision sometimes taking antibiotics

Prevention Although it's not always possible to prevent boils especially with a compromised immune system Wash hands regularly with mild soap Thoroughly clean even small cuts and scrapes Keep wounds covered Keep personal items personal

Boil Carbuncle

Cellulitis Cellulitis is a common potentially serious bacterial skin infection Cellulitis appears as a swollen red area of skin feels hot and tender it may spread rapidly Skin on lower legs is most commonly affected though cellulitis can occur anywhere on body or face Infected left shin

Cellulitis may affect only skin's surface may also affect tissues underlying skin can spread to lymph nodes and bloodstream Left untreated the spreading infection may rapidly turn life-threatening It's important to seek immediate medical attention if cellulitis symptoms occur

Symptoms Possible signs and symptoms of cellulitis include: Redness Swelling Tenderness Pain Warmth Fever The changes in the skin may be accompanied by a fever Over time, the area of redness tends to expand Small red spots may appear on top of the reddened skin less commonly, small blisters may form and burst

Risk factors Several factors can place you at greater risk of developing cellulitis: Known injury Weakened immune system Skin conditions Chronic swelling of arms or legs (lymphedema) History of cellulitis Intravenous drug use Obesity

Complications Once below skin Recurrent episodes of cellulitis the bacteria can spread rapidly throughout body entering lymph nodes and bloodstream Recurrent episodes of cellulitis may damage the lymphatic drainage system cause chronic swelling of the affected extremity In rare cases infection spread to the deep layer of tissue the fascial lining necrotizing fasciitis

Tests and diagnosis The appearance of the skin Blood tests or a wound culture

Treatments and drugs Cellulitis treatment usually is a prescription of oral antibiotic a drug that's effective against both streptococci and staphylococci Elevating the affected area, may speed recovery

Prevention To help prevent cellulitis and other infections, take these precautions when you have a skin wound: Wash your wound daily with soap and water Apply an antibiotic cream or ointment Watch for signs of infection

People with diabetes and those with poor circulation take extra precautions to prevent skin wounds treat any cuts or cracks in the skin promptly Good skin-care measures include the following Inspect feet daily Moisturize skin regularly Trim fingernails and toenails carefully Protect hands and feet Promptly treat any superficial skin infections such as athlete's foot

The outline in pen was drawn when the patient presented to the emergency room. Within a day the skin infection had enlarged and blisters (bullae) had formed. Cellulitis is a serious infection requiring intravenous antibiotics.

Cellulitis is usually a superficial infection of the skin Cellulitis is usually a superficial infection of the skin. But if severe or if left untreated, it can spread into your lymph nodes and bloodstream. Pictured here is mild cellulitis (left) and severe cellulitis (right). Severe redness and swelling are typical in cellulitis. The skin is usually very warm to the touch.

Necrotizing fasciitis A rapidly progressive inflammatory infection of the fascia with secondary necrosis of the subcutaneous tissues Necrotizing fasciitis may occur as a complication of a variety of surgical procedures medical conditions including cardiac catheterization diagnostic laparoscopy

The 3 most important causative bacteria are as follows: Type I, or polymicrobial Type II, or group A streptococcal Type III gas gangrene, or clostridial myonecrosis The frequency of necrotizing fasciitis has been on the rise because of an increase in immunocompromised patients diabetes mellitus cancer alcoholism vascular insufficiencies organ transplants HIV infection

Pathophysiology Necrotizing fasciitis is characterized by widespread necrosis of the subcutaneous tissue and the fascia Historically, group A beta-hemolytic Streptococcus has been identified as a major cause of this infection

Group A hemolytic streptococci and Staphylococcus aureus, alone or in synergism, are frequently the initiating infecting bacteria However, other aerobic and anaerobic pathogens may be present, including the following: Bacteroides Clostridium Peptostreptococcus Enterobacteriaceae Coliforms (eg, Escherichia coli) Proteus Pseudomonas Klebsiella

Prognosis The reported mortality in patients with necrotizing fasciitis has ranged from 20% to as high as 80% Poor prognosis in necrotizing fasciitis has been linked to infection with certain streptococcal strains Necrotizing fasciitis survivors may have a shorter life span than population controls owing to infectious causes such as pneumonia, cholecystitis, urinary tract infections, and sepsis

Complications Complications may include the following: Renal failure Septic shock with cardiovascular collapse Scarring with cosmetic deformity Limb loss Toxic shock syndrome Septicemia is typical and leads to severe systemic toxicity and rapid death unless appropriately treated

Medication Summary Antibiotic therapy is a key consideration Possible regimens include a combination of penicillin G and an aminoglycoside (if renal function permits), as well as clindamycin (to cover streptococci, staphylococci, gram-negative bacilli, and anaerobes)

Signs and symptoms Rapid progression of sever pain with fever , chills (typical) Swelling , redness, hotness, blister, gangrene and necrosis Blisters with subsequent necrosis Diarrhea and vomiting (very ill) Organ failure Mortality as high as 73 % if untreated

Diagnosis A delay in diagnosis is associated with a grave prognosis and increased mortality Clinical-high index of suspicion Blood tests CBC-WBC , differential , ESR BUN (blood urea nitrogen) Surgery debridement- amputation Radiographic studies X-rays : subcutaneous gases CT or MRI Microbiology Culture &Gram's stain ( blood, tissue, pus aspirate) Susceptibility tests

Pyomyositis Acute bacterial infection of skeletal muscle, usually caused by Staph. aureus No predisposing penetrating wound, vascular insufficiency, or contiguous infection Most cases occur in the tropics 60% of cases outside of tropics have predisposing RF: DM, EtOH liver disease, steroid rx, HIV, hematologic malignancy

Pyomyositis Hx of blunt trauma or vigorous exercise (50%), then period of swelling without pain. 10-21 days later, pain, tenderness, swelling and fever, Pus can be aspirated from muscle 3rd stage: sepsis, later metastatic abscesses if untreated Dx: X-ray, US, MRI or CT Rx: surgical drainage +abx

Other Specific Skin Infections Epidemiology Common Pathgen(s) Therapy Cat/Dog Bites Pasturella multocida; Capnocytophaga Amox/clav (Doxy; FQ or SXT + Clinda) Human bites Mixed flora eikenella corrodens Hand Surgeon; ATB as above Fresh water injury Aeromonas FQ; Broad Spectrum Beta-lactam Salt water injury (warm) Vibrio vulnificus FQ; Ceftazidime Thorn , Moss sporothrix schenckii   Potassium iodine Meat-packing Erysipelothrix Penicillin Cotton sorters Anthrax Cat scratch Bartonella Azithromycin